HOMEOSTASIS - POSITIVE VS NEGATIVE FEEDBACK Flashcards
In Homeostasis we have a thing called Positive and Negative feedback with Negative feedback being the most common.
This is a question we can’t promise will come up but there is a strong likelihood as it has come up a lot within the last few years.
So let’s start learning about each one so you will be able to explain them if required.
Positive Feedback is a mechanism that amplifies or increases the direction of change to restore homeostasis.
The best example I can give with Positive feedback is Childbirth:
Oxytocin is continually released during labor to intensify uterine contractions, leading to further release of oxytocin.
Another example of positive feedback is a fever response to infection
When the body detects an infection, it initiates a fever response to increase body temperature and aid in fighting the infection
Another example for Positive feedback is blood clotting process, when a blood vessel is damaged, platelets release chemicals that attract more platelets to the site, forming a clot to stop bleeding.
Another Positive feedback example is milk production from Mother as a baby suckles at the breast, it stimulates nerve endings that signal the release of more milk from the glands.
What is the purpose of Positive Feedback in Homeostasis?
To rapidly and effectively bring about a physiological change in response to a specific condition or stimulus.
What are the components of a Positive Feedback loop?
Stimulus, sensor/receptor, control center, effector, and response
How does Positive Feedback differ from Negative Feedback?
Positive feedback amplifies the response, while negative feedback reverses or opposes the response to maintain stability.
Now let’s move on to Negative Feedback …
What is negative feedback?
A regulatory mechanism in which a change in a variable triggers a response that opposes the initial change, thus restoring equilibrium.
How does negative feedback regulate body temperature?
When body temperature increases, receptors in the skin and brain detect the change and trigger responses to cool the body down, such as sweating and vasodilation.
What is an example of negative feedback in blood glucose regulation?
When blood glucose levels rise after a meal, the pancreas releases insulin to stimulate the uptake of glucose by cells, thus lowering blood glucose levels back to normal.
Why is negative feedback important in maintaining homeostasis?
It allows the body to continuously monitor and adjust various physiological variables to prevent extreme deviations that could be harmful to the organism.
